"Sundance Film Festival had been subject to a cyberattack, causing network outages that shut down our systems," the festival said in a statement. "Screenings were not affected. The show goes on and our artists' voices will be heard."

The festival said it didn't have details about the source of the attack.

The attack was announced through the festival's official Twitter account shortly before 11 a.m. PT, followed by an update about half an hour later saying that some segments of its box office were being restored. By early afternoon, the festival's website said all systems were back up and running.

We have been subject to a cyberattack that has shut down our box office. Our artist's voices will be heard and the show will go on.